The most fundamental distinction in geographic representation
PROJCS["TM65 / Irish Grid",
GEOGCS["TM65",
DATUM["TM65",
SPHEROID["Airy Modified 1849",6377340.189,299.3249646, AUTHORITY["EPSG","7002"]],
AUTHORITY["EPSG","6299"]],
PRIMEM["Greenwich",0, AUTHORITY["EPSG","8901"]],
UNIT["degree",0.01745329251994328, AUTHORITY["EPSG","9122"]],
AUTHORITY["EPSG","4299"]],
UNIT["metre",1,
AUTHORITY["EPSG","9001"]],
PROJECTION["Transverse_Mercator"],
PARAMETER["latitude_of_origin",53.5],
PARAMETER["central_meridian",-8],
PARAMETER["scale_factor",1.000035],
PARAMETER["false_easting",200000],
PARAMETER["false_northing",250000],
AUTHORITY["EPSG","29902"],
AXIS["Easting",EAST],
AXIS["Northing",NORTH]]